Guide plates for rotary regenerator



July 12, 1960 R. H. MULLER 2,944,798

GUIDE PLATES FOR ROTARY REGENERATOR Filed June 22, 1955 I8 1 i 75 F 26 24 35 i 2.1. I 6 i. 2, I W E wix V g m INVENTOR. i ezz AZ/Wzz/fer AGE/V i ed SttltS sp te-'19 f "i Y GUimsmeritsiron RoTARY REGENERATOR Rohert H. Muller, Wellsville, 'assignortto The Air reheater Corporation,-New York, -N.Y., a corporation 'orNew'York q Fi1sa"June22,'w5s',senNm-srmoti' 1; Claims. crust-27o The present inyeiition relates to heat exchangers of the rotary "regenerative "type, and "particularly it relates to an arrangement of auxiliary heat 'exchange' and flow plates which greatly "improve the operating efliciency er such heat exehanger in a rotar -regenerate,

e s a exehange s: t typ -lierei'r'1referredto, La cylindrical rotorcarryingcompart- 2,944,798 Patented July 12,

. 2 read "in conjunction with the accompanying s' "in which: i

' Figure 1 is a longitudinal section an reger- 't'ive heat exchanger-arranged according to inventign. Fi ure 2 is arragnientary sectional elevation of the ueviceass enfmm line Z2 of Figure :1.

partmems by radial artitions or diaphr'g m'siuiw a pi s 'h sears. L l

Figure 3 is a rr'a mentarysectional elevation 6f a' sliglit- 1y modified formofthe invention. I

in Figures 1 and 3 the nunier'al 10 ees lindricalshel1 ofa retor divided into "sects connect it to a rotor post 12 which isv and reduction gearing 13 to turn the' r'slo ly'a-hout its axis. 'The rotor compartments ontain regenerative heat transfer material 14 which first absorb heat gases enterin the preheaterthroughja duct 'I'S fromaboiler orother source to be discharged heat transfer material'thr'oug'h an outlet-duct 16. as the rotor turns slowlyaboutits axis, the heat'ed material: 14

[is .moved into the streamf of air admitted throughl'lthe dufct"17. After passingove'r theheat exchange material arid b t n ea r' hs sf a t eteam t. set'si s t is conveyed to a boiler furnace or other "place of use housing .l enclosing rotor 1 .tured at 22 and in alignment with ducts .15

' and discharge streamsZof gas or air through. To dir'ec't fluid flowing through th'ebanks of heat exchange element,- imperforate-bafl les or flow plates are provided to extend diagonally from one :;e nd of an element Bank to the-opposite'end of-a radially spaced :b k of similar element sections. v I

' When the heat exchange 'element 'of'a "rotaryregenerative heat exchanger is arranged in concentric banks there is a detrimental tendency for the high velocity gas and air to flow axially through the passageway between spaced heat exchange elements and pile-up at the far end of the rotor passageway causing uneven heating and inelficient use of heat exchange matrix. Moreover, opposite sides of the diagonal baflle members are subjected to op posite extremes in temperature since they are in direct contact with the hot and cold fluids traversing the heat ,prelfieater.

Th heat ha l m i l s m nned, in/sat s es? x ll cp s iq an ra y r sl iv eni lt asnzs 1 P ov d a a assa e y 0. 7 .t eflQ at nit q t' i f *I s d -r19 direstdifl f tb aush the sectionsof heat exchange element, ;they are supported in concentric relation about the centfiallypositioned rotor p s 1 b m mteb s t w ic f x dbe nesp ra h a m and qn nd ah atiexehanse section 1 4 to theaxially. opposite end-of-a radially spaced I sectionl l when er an in t smsns eashkstl mem sr x s between radially spaced sections of heating element constitutes a passage wall common to a pair of oppositely exchanger. The diagonal baffle member is in a highly 1 effective heat transfer zone because of the high temperature head between opposite sides thereof and his therefore an object of this invention. to reduce the temperature gradient across eachdiagonal baffle member so as to effect a decrease of heat transfer at a zone where it would materially decrease the overall efllciency of the heat exchanger.

Furthermore, in rotary regenerative heat exchangers of the type herein disclosed, a highly eflicient matrix requires Such an element is highly efficient from.

tapering passageways as illustrated by passageways 23 and 25 of Figure 1. Withthis' arrangement, cold air or hot gases flowing axially into the spaces between concentric masses of heat exchange element strike a diagonal baflile member and are turned in a general radial direction to flow through the perforate heat exchange mass 14. After traversing the perforate heat exchange mas-s the air or gas is again'turned by a baflle member adjacent the op posite side of the heat exchange mass and forced to flow generally in an axial direction out of the heat exchanger into an outlet duct.

In accordancewith this invention, a series of additional flow plates in theform of heat transfer elements 26 are arranged-parallel to the diagonal baflle members so as to extend diagonally from axially spaced ends of the rotor to the radially spaced sections of heat exchange element 14. These sheets preferably are of various forms frequently used as. heat exchange element in rotary regenerative heat exchangers. Specific forms most adaptable to, use as flow plates include imperforate corrugated or undulated sheets having a relatively low surface to volume ratio. However, other forms including tab surface provide desirable properties and may be especially adapted to use under certain circumstances.

An arrangement of flow plates 26 disposed according to this invention would force an even distribution of fluid flow through the radially spaced heat exchange element sections thereby substantially improving the heat transfer efiiciency of the heat exchanger. Since the intermediate flow plates would confine the fluid to relatively thin layers, the temperature change adjacent the diagonal flow plate 24 would be confined to the layer adjacent thereto which would in turn reduce the temperaturehead across. the diagonal flow'plate and decrease the heat transfer at this point. e By supplying a large mass of material on the hot side of the heat exchange element, the tendency toward fire would. be substantially reduced, since the temperature would be substantially modified by the heat exchange surface having a relatively low surface to mass ratio, Althoughit is immaterialto this. invention Whether the auxiliary flow plates are installed as individual sheets or as prefabricated bundles, bundling by spot or tack welding the individual sheets togethenoffers certain advantages of assembly. 7 M 7 Further advantages of flow distribution may be achieved by the use of auxiliary flow plates that extend past the ends of the primary element as illustrated by elements 28 of Figure 3. By fanning out ends of the flowplates, fluid flow is smoothed out so the pressure drop of fluid passing through the rotor may be substantially reduced. What I claim is:

1. A rotary regenerative heat exchanger or the like having a cylindrical rotor shell joined to a centrally positioned rotor post by radial partitions which form a series of sector shaped compartments; a housing surrounding the rotor and provided opposite the latter withjendplatcs including imperforate portions between spaced apertures; inlet'andoutlet ducts connected to said apertured end plates to direct streams of hot gas and. relatively cooler air to and through the rotor; regenerative heat transfer 'in'aterial carried by the rotor comprising a plurality of perforate element sections lying in banks parallel to.,the rotor axis and radially spaced to provide flowtpassageways extending between the axially spaced inlet and outlet ducts; imperforate flow sheets extending between opposite ends of radially spaced element sections dividing each passageway into a pair of oppositely tapering sections; and a plurality of intermediate flow sheets between adjacent banks of heat transfer material parallel to said imperforate flow sheets spaced to provide a plurality of pas- 'sageways from the ends of the rotor to axially spaced portions of the element sections.

r 2. A rotary regenerative heat exchanger or the lik a. "9,944,79 r -7 'r as defined in claim 1 wherein the intermediate flow sheets are provided with extended surface to effect an increase in heat transfer etficiency thereof.

3.A rotary regenerative heat exchanger or the like as defined in claim 2 wherein the intermediate flow sheets extend axially of the banks of element sections and are axially divergent to guide fluid flowing through passageways therebetween and thereby prevent excessive drop in fluid pressure thereof. I

4. A rotary regenerative heat exchanger or the like as defined in claim 1 wherein ends of the intermediate flow sheets diverge axially of the element section banks to direct fluid flow past ends of the perforate element sections.

5. A rotary regenerative heat exchanger or the like having a cylindrical rotor shell joined to a centrally positioned rotor post by radial partitions which form a series of sector shaped compartments; a housing surrounding the rotor and provided opposite the latter with end plates including imperforate portions between spaced apertures; inlet and outlet ducts connected to said apertured end plates to direct streams of hot gas and relatively cooler air to and through the rotor; a plurality of heat exchange element sections having a high surface to mass ratio lying in banks parallel totbe rotor axis, said sections being radially spaced to provide flow passageways therebetween; imperfor a'te flow 'sheets extending between vop- 7 posite ends of radially spaced element sections to;diyide each passageway .into avpair of oppositely taperingsections; and intermediate flow sheets parallel to said imperforate flow sheets spaced. to provide a plurality of passageways between. an end of the rotor and axially spaced portions of the element sections, said intermediate flow sheets having a relatively low surface to mass ratio providing a high resistance to fire.

I 6. A rotary regenerative heat exchanger as defined in claim 5 wherein the intermediate flow sheets are placed only in those sections of each flow passageway adjacent the inlet for the'hot gas.

References Cited in the file of this patent UNITED STATES PATENTS Karlsson June 1, 1954 

